/*
 * Copyright 2012-2014 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package lodsve.core.condition;

import java.util.Map;

import lodsve.core.condition.ConditionalOnJava.JavaVersion;
import lodsve.core.condition.ConditionalOnJava.Range;
import org.springframework.context.annotation.Condition;
import org.springframework.context.annotation.ConditionContext;
import org.springframework.core.Ordered;
import org.springframework.core.annotation.Order;
import org.springframework.core.type.AnnotatedTypeMetadata;

/**
 * {@link Condition} that checks for a required version of Java.
 *
 * @author Oliver Gierke
 * @author Phillip Webb
 * @see ConditionalOnJava
 * @since 1.1.0
 */
@Order(Ordered.HIGHEST_PRECEDENCE + 20)
class OnJavaCondition extends SpringBootCondition {

    private static final JavaVersion JVM_VERSION = JavaVersion.getJavaVersion();

    @Override
    public ConditionOutcome getMatchOutcome(ConditionContext context,
                                            AnnotatedTypeMetadata metadata) {
        Map<String, Object> attributes = metadata
                .getAnnotationAttributes(ConditionalOnJava.class.getName());
        Range range = (Range) attributes.get("range");
        JavaVersion version = (JavaVersion) attributes.get("value");
        return getMatchOutcome(range, JVM_VERSION, version);
    }

    protected ConditionOutcome getMatchOutcome(Range range, JavaVersion runningVersion,
                                               JavaVersion version) {
        boolean match = runningVersion.isWithin(range, version);
        return new ConditionOutcome(match, getMessage(range, runningVersion, version));
    }

    private String getMessage(Range range, JavaVersion runningVersion,
                              JavaVersion version) {
        String expected = String.format(
                range == Range.EQUAL_OR_NEWER ? "%s or newer" : "older than %s", version);
        return "Required JVM version " + expected + " found " + runningVersion;
    }
}
